mybe it could use a direct connection between both ends of the conversation, like on a file transfear. i'm not into the protocol so...
i'd use it, it's a cool feature, i remeber when i used ICQ that i liked chatting like that cause u could tell how fast the other person was typing, and it made me think more before writing
on a direct 1on1 conversation is very usefull cause it makes it way closer to a voice chat and if u can write and look at the screen at the same time... then.. wow